Suction cleaner



Aug. 31, 1943. T. A. sToNER 2,328,236

SUCTION' CLEANER Filed Dec. '7, 1939 Y 2.Sheets-Sheet l mw ,L 1f,

".1 z/ I Y z 3( I I i mvEN-ron l I wmm 14.670001' ATTORNEY Aug. 31, 1943.

T- A. STONER SUcTIoN CLEANER Filed Dec 7, 1939 2 Sheets-Sheet 2 INVENTQR fha/:zas A. @S70/zer ATTORNEY Patented Aug. 31, 1943 UNITED -sTATEs lPATi-:NT oI-Flcs SUCTION CLEANER Thomas A. Stoner, North Canton, Ohio, assigner to The Hoover Company, North Canton, Ohio, a corporation of Ohio Application December 7, 1939, Serial No. 307,968

4 Claims. v (Cl. 183-51) This invention relates to improvements in suction cleaners, and more particularly to an improved form of muiller to reduce the noise caused by operation of the suction cleaner.

An object of the invention is to provide a new and improved muiller for suction cleaners. Another object is to provide a combination resonant-absorption muffler for suction cleaners, wherein the `resonant portion of the muiiler attenuates certain undesirable sound waves, and the absorption portion reduces noise throughout the audible range. A further object is to provide a mufiler adapted to operate in the dirt-laden air stream of a suction cleaner. Another object is to provide a resonant muilier that is easily disassem bled for removing foreign matter therefrom. Other objects and advantages of the invention will be apparent from th specification and drawings, wherein Figure 1 is a side elevation with parts broken away to illustrate one embodiment of the resonant-absorption muffler attached to the exhaust passageway of a suction cleaner;

Figure 2 is a fragmentary perspective view partly lin section of the resonant-absorption muiiier removed from the cleaner;

Figure 3 is another embodiment of the invention showing the resonant muiller telescoped about a flexible bellows to reduce the over-all length of the murder construction, and

Figure 4 is an enlarged fragmentary exploded perspective view of the muiller shown in Figure 3.

'I'he embodiment of the invention shown in Figures 1 and 2 comprises a suction cleaner having a casing 9 provided with a nozzle I0 communicating through a suction passageway I1 with an eye I8 of a fan chamber I I. Removably mounted on the casing 9 is a housing I3 which encloses an unshown motor for rotating a fan I2 and a pulley 2i which has driving connection with a belt 20 to operate a surface contacting member I9 rotatably mounted in the nozzle I0. A handle I4 is provided with a bail l5 pivotally mounted on the casing 9 which is supported on a pair of front and rear wheels I6.

Extending rearwardly from the fan chamber is an exhaust passage 25 terminating in an annular flange 26 to which a member 21 is removably attached by means of a pair of bolt and nut connections 28. The mouth of` a porous dirt lter bag 29 is removably attached to an annular lshoulder 30 on the member 21 by means of a clamping ring 3|, and the upper end of the bag 36, the latter having a pair of spaced arms 31 which are pivotally mounted by a pin 33 to a pair of spaced arms 39 extending rearwardly from the member 21. A torsion spring 40 is incorporated in the hinge and acts to support the weight of the. muffler 33 to prevent the full weight of the latter from resting on the lower bag wall when thehandle is moved to the conventional substantially vertical storage position. In order to connect the muiiier tothe exhaust passageway 25, a flexible bellows 42 is provided which permits the muiller to be inclined slightly in an upward direction following generally the inclination of the bag 29. Since the hinge connection is above the central longitudinal axis of the bellows 42, the lower corrugations 43 of the latter will expand and the uppercorrugations contract when the handle and the mufller are moved upwardly, so as not to constrict the discharge passageway into the dirt bag 29.

The muiller casing section 36 comprises an annular outer wall 45, a radial end wall 46, and a reduced annular wall 41 which is frustro-conical in shape and flares outwardly toward the cleaner exhaust passageway 25. The conical wall 41 terminates in an annular ring 48 from which integrally extend the hinge arms 31, and is provided with an annular recess in which one end of the bellows 42 is removably attached by a spring ring 49, and the opposite end of the bellows is secured in a like manner to an annular shoulder 34 on the member 21. The cooperating muffler casing section 35 comprises a cylindrical shell 55 provided intermediate its ends with a radially extending flange 50 having a peripheral shoulder 5I for removable connection with the wall 45 by means of a plurality of screws 52. Punched out of the wall of the metal shell 55 are tabs 56 which are secured to the end wall 50 by means of rivets 51. The openings 58 resulting from forming the tabs 56 are closed by annannular ilange 54 on the end wall 50. A portion 60 of the muiiler casing section 35 extends inwardly into the enlarged portion of the casing section 36 and is spaced from the end Wall 46 to provide an annular opening 6I which is covered b ya perforated metal member 62. The perforated member 62 is seated in or rabbeted portions63 and 64 respectively of the casing sections 35 and 36.

The re-entrant portion 60 of the shell 55, the walls 45 and 46, and the end wall 50 cooperate to form an annular resonant chamber 10 which isl concentric with the muilier passageway 14, and the entrance 6I is of a predetermined area. with respectto the volume of the resonant chamber 10 -to attenuate the objectionable sound waves ameter throughout its length, and the mufiler 83 is provided with the conical passageway 13 which discharges into the muiller exhaust passageway 14 adjacent the entrance 5| of the resonant chamber 18.

In operation, assume the motor is rotating the fan |2 and the surface agitating member I8, and the cleaner is being moved over the surface being cleaned. Operation of the cleaner produces sound waves over the entire audible range, and some of these sound waves are of such frequency as to be sensitive to the operator. In order to eliminate, for example, the fan noise, which is n a relatively limited range of frequency, the resonant chamber 18 is constructed to a predetermined volume and the entrance 8| to a predetermined area. Upon discharge of the dirtladen air into the muiiier passageway 18, the sound waves pass through the screened opening 8| into the concentric annular resonant chamber 18, and are attenuated in the closed resonant chamber to reduce the undesirable fan noise. The member 82 removes the foreign matter from the dirt-laden air without aecting the eillciency of the resonant muiiler. 'I'he energy of the sound waves passing through the muiller passageway 18 are also reduced by the absorption eifect of the sound-absorbing material 1| and its metallic shell 55. Finally, the sound waves that escape into the filter bag 28 have been attenuated and absorbed to such a degree that the resulting noise is negligible.

Another embodiment of the invention is shown in Figures 3 and 4 and comprises a suction cleaner 88 similar to that described in the foregoing embodiment and is provided with the exhaust passageway 25 and the iiange 25 to which. is removably mounted the member 21 having an annular flange 38 on which a dust-filtering bag 8| is detachably connected by the clamp 8|.

A muier, indicated generally at 82, includes a casing formed of two sections 83 and 88, the latter being provided with a pair of spaced arms 85 which are pivotally mounted by a pin 88 to a pair of arms 81 extending rearwardly from the bag supporting member 21. A torsion spring 88 about the pivot pin 88 acts to support the weight of the muiller 82 to prevent the full weight of the latter from resting on the lower wall of the bag 8| when the handle is moved to the conventional substantially vertical storage position. In order to connect the muliler to the exhaust passageway 25, a flexible bellows 18 is supported at its lower end in the member 21 and its upper end is removably supported in an annular groove 11 on a contour and which abuts the extreme edges 88 and 81 of the collar 18 and the outer wall 88 respectively, and is removably secured thereto by suitable bolts threaded into the outer muiller wall 88. The end wall 85 cooperates with the collar 18, casing walls 88, 88, 82 and 88 and the partition 8| to define a. pair of resonant chambers 88 and 88. Entrances 88 and |8| to the resonant chambers 88 and 88 respectively, are provided by recessing the collar 18 from its outer edge 88, the end wall 85 cooperating to denne one edge of these entrances. The entrances are covered vby perforated metal members |82 which are seated in the collar 18 and abut against the end wall 85. The entrances |88 and |8| are of predetermined area with respect to the volumes o! their respective resonant chambers, whereby each resonant chamber will attenuate a selected range of sound waves to thereby muiile the cleaner noise.

The resonant chambers 88 and 88 are L-shaped and telescope the flexiblebellows 18 whereby the over-al1 length of the resonant muiiier and bellows is reduced so as not to extend a great disstance into the illter bag 8|, and since the resonant muiiier telescopes. the bellows 18 in spaced relation, the latter ilexes within the confines of the muiller when the handle and filter bag are raised and lowered with respect to the cleaner casing.

Extending outwardly from the end wall 85 of the muiller casing section 88 is a tubular shell |85 which is lined with a suitable sound-absorbing material |88, such as sponge rubber, and defines a discharge passageway |81 which communicates with the cleaner exhaust passageway ,25.

Disposed within the filter bag 8| is a dust-fil-v tering bag 88 composed of paper, or the like, and has a re-entrant portion |88 that snugly fits the shell |85 and projects beyond the upper end thereof to form a deilector to prevent dirt from dropping back into the muiiler passageway |81. A clamp I8 removably secures the paper bag |88 to the shell |85. The outer bag 8| is provided with an unshown opening for removing the paper bag |88 and to disconnect the latter from the mui'iler.

In operation, assume the cleaner 88 is removin g dirt from the surface being cleaned. The sound waves in the dirt-laden air stream being discharged from the exhaust passageway 25 pass through the screened openings |88 and |8| into I the resonant chambers 88 and 88. The entrances tion 88.

|88 and |8I being of predetermined areas with respect'tovthe volumes of the resonant chambers 88 and 88 respectively, attenuate the sound waves to reduce the noise produced by the suc- -tion cleaner. Each resonant chamber 88 and 88 may be of different volume for attenuating sound waves within certain bands of frequencies. The members |82 remove the foreign material from the dirt-laden air without aiectlng the eillciency of the resonant chambers. c The energy of the sound waves passing through the muiller exhaust passageway |81 are reduced by the absorption effect of the sound-absorbing material |88 and its metallic shell |88, to thereby reduce the energy of the sound waves over the entire audible range.

Whmitisdesixedtoclennthe nmiler,the easingendwnllisxuno'vedfmmthewlll 88to expose the resonant chambers 88 and 88 whereby the foreign material may easily be removed.

Plum theforegdng it will be perceived that I Xillnvielllwllledaresonant-absorp-Y tion muiiler which functions to attenuate sound waves in relatively certain frequencies and also reduces the energy of the sound waves over the entire audible range, and that the resonant chambers are adapted to attenuate sound waves in dirt-laden air.

I claim:

1. A sound-reducing resonant mulder adapted to be mounted on a cleaner body in communication with the suction system of a suction cleaner and comprising, a muiiier casing and perforated conduit cooperating to define a resonant chamber of a volume calculated to reduce sound vibrations in the moving air stream in a suction cleaner, said resonant chamber extending longitudinally and laterally beyond said conduit, and means connecting said conduit to said cleaner body and to the suction system, said resonant chamber telescoping said connecting means, extending therealong and slightly therebeyond laterally to provide protecting means for said connecting means,

2. In a suction cleaner, a cleaner body having an exhaust passageway for dirt-laden air, a bag for receiving the dirt-laden air, a sound-reduc ing muiiier attached to said cleaner body and having a resonant chamber and sound-absorbing material, a conduit in said muilier communicating with said sound-absorbing material and having perforations leading to said resonant chamber, said conduit communicating with said exhaust passageway and said bag, said bag being-attached to and supported by saidmuiller, said resonant chamber attenuating the sound waves insaid dirt-laden air as the latter passes said perfora- I tions in said conduit, and said sound-absorbing material absorbing the energy of the sound waves -in said dirt-laden air prior to discharge into said bag.

3. In a suction cleaner, a cleaner body having an exhaust passageway for dirt-laden air, a bag attached to one end of said cleaner body for tiltering the dirt-laden air, a sound-reducing muffler attached to said one end o said cleaner body and having a resonant chamber and a conduit having a portion thereof provided with perforations leading to said resonant chamber. soundabsorbing material lining another portion of said conduit. said conduit communicating with said exhaust passageway and said bag, said muiiler being completely disposed withinv said bag in spaced relationship to the walls thereof and being of such length asnot to interfere with the ltering operation of said bag, said resonant chamber attenuating the sound waves in/said dirt-laden air as the latter passes said perforations in said conduit, and said sound-absorbing material absorbing the energy of the sound waves in said dirt-laden air prior to discharge into said bag.

4. In a suction cleaner, a cleaner body having an exhaust passageway for `dirt-laden air, a bag attached to one end of said cleaner body for ltering the dirt-laden air, a mufiier casing and perforated conduit cooperating to dene a resonant chamber of a volume calculated to reduce sound vibrations in the dirt-laden air, said resonant chamber extending longitudinally and laterally beyond said conduit, means connecting said conduit to said cleaner body land said exhaust passageway, said muffler casing being disposed com- 

